Several states have implemented systems for monitoring conditions on potentially congested public highways. Such systems typically incorporate sensors or speed traps installed at various locations to monitor current traffic speeds at those locations. Often, the monitoring systems also include video cameras at different locations to provide continuous images and live feeds of conditions.
FIG. 1 shows a prior art traffic information system, generally designated by reference numeral 10, for monitoring traffic on a public highway system. Systems such as this have been implemented by several states and other governmental agencies.
The information system of FIG. 1 includes a plurality of speed sensors or traps 12 at various locations along a public highway or along a network of public highways. The speed sensors might typically be spaced at intervals ranging from a tenth of a mile in highly congested areas to perhaps over a mile in less congested areas. Different sensors are positioned in different directions of travel.
The information system also includes a plurality of video cameras 14. The video cameras are positioned at chosen vantage points to allow highway personnel to view critical stretches of highway. The cameras do not necessarily have a one-to-one correlation with the speed sensors.
Signals from the sensors and cameras are routed to a central facility 16 for monitoring by highway personnel. The central facility typically includes one or more computers 18 for receiving speed sensor data and for displaying it in a meaningful way. For instance, the central facility might have a large wall-mounted map with computer-controlled lights that flash to indicate highway locations where speeds are unusually low.
Camera video signals are routed to a video switch 20 within the central facility and distributed to one or more monitors 22. Typically, there are fewer monitors than available video signals, so the video switch is programmed to cycle through the signals in a predetermined sequence. Alternatively, the video switch might be controlled by one of computers 18. In this case, there might be some type of logic that determines which video signal is routed to a particular monitor. For example, the computer might be programmed to cycle through only those video signals that correspond to highway locations that are experiencing congestion.
The information system also includes a database 24 maintained by computers 18. The database is used to store historical data relating to highway conditions. In most cases, the database will not contain video, but instead will contain historical speed data.
Public highway monitoring systems are used by both highway personnel and news media. In addition, many systems are now being used to provide realtime traffic information to the public via the Internet. For example, traffic conditions can currently be accessed through the Internet for the following areas at the indicated Internet sites (designated by their uniform resource locators or URLs):
Houston "http://herman.tamu.edu/houston-real.html" PA1 San Diego "http://www.scubed.com/caltrans/sd/bit_map.html" PA1 Los Angeles "http://www.scubed.com/caltrans/la/la_transnet.html" PA1 Manitoba: "http://umtig.mgmt.umanitoba.ca/default.htm" PA1 Seattle: "http://www.ivhs.washington.edu/trafnet/"
To implement these sites, a server computer 26 is either located at the central facility 16 or connected for high-speed communications with the central facility. The server computer has a connection to the Internet.
The server computer is connected to access sensor data from the traffic information system. It uses the sensor data to create a continuously-updated map that indicates current traffic conditions.
While these Internet sites are useful, improvements are needed. One problem with the sites is that they display traffic information in different ways and require different user instructions to provide traffic information. While it would be desirable to create a common user interface that would access and display data from all of the available public highway monitoring systems, this is difficult because the data from the various systems is available only in different formats, depending on the particular proprietary format used by each monitoring system.
Another problem lies in the fact that information is presented in visual formats that are not immediately useful to users. For example, typical user interfaces for traffic monitoring systems show rough maps having roads that are divided into sections corresponding to locations of speed sensors. The sections are color-coded to indicate current speeds measured by corresponding sensors. For example, red might indicate "stop-and-go" conditions, yellow might indicate "slow" conditions, and green might indicate "normal" conditions. Icons might be used to indicate traffic incidents such as construction zones and crashes. While such user interfaces indeed present the available information, they do not do so in a way that is particularly useful to a person planning a commute across town.